Numbers 1:3

1:3 You and Aaron are to number all in Israel who can serve in the army, those who are twenty years old or older, by their divisions.

Numbers 1:45

1:45 All the Israelites who were twenty years old or older, who could serve in Israel’s army, were numbered according to their families.

Numbers 3:47

3:47 collect five shekels for each one individually; you are to collect this amount in the currency of the sanctuary shekel (this shekel is twenty gerahs).

Numbers 26:2

26:2 “Take a census of the whole community of Israelites, from twenty years old and upward, by their clans, everyone who can serve in the army of Israel.”

Numbers 26:4

26:4 “Number the people from twenty years old and upward, just as the Lord commanded Moses and the Israelites who went out from the land of Egypt.”